A light receiving device for use in optical communication can include an avalanche photodiode (hereinafter referred to as APD) capable of receiving light by amplifying a light receiving signal. The APD is a photodiode in which a phenomenon called avalanche multiplication is utilized to increase light receiving sensitivity. By including the APD, the light receiving device can receive a light signal attenuated over long-distance transmission.
In Patent Literature 1, a bias circuit including a temperature sensor, a memory, and a central processing unit (CPU) is used. Specifically, the memory stores temperature data for a bias voltage for an APD, and the CPU controls the bias voltage for the APD based on the data stored in the memory. With this configuration, the APD can be driven at the optimal bias voltage at any time.